Safety helmet



Jan, 30, 1968 Y D. D. WEBB 3,365,725

SAFETY HELMET Filed Feb. 1o. 1966 DANIEL D. WEBB ATTORNEYS United StatesPatent O 3,365,725 SAEETY HELMET Daniel D. Webb, Birmingham, Mich.,assigner to American Safety Equipment Corporation of Michigan,Southfield, Mich.

Filed Feb. 10, 1966, Ser. No. 526,586 2 Claims. (Cl. 2 3) This inventionrelates to a crown pad for a safety helmet.

Safety helmets may be provided with padding at the dome or top of theinterior of the helmet, so that the hard interior surface of the helmetrests more comfortably upon the top of the wearers head during use.

It is au object of this invention to provide a safety helmet crown padwhich is readily `capable of deflection to accommodate heads ofdifferent shapes, and which traps air contained therein at times ofimpact to form a substantially sealed pneumatic cushion for absorbingexternally applied loads due to impact.

This and other objects and advantages of this invention will becomeapparent from the following specification when considered in conjunctionwith the accompanying drawings.

In these drawings:

FIG. l is a cross-sectional elevation through a safety helmet embodyingthe crown pad of this invention;

FIG. 2 is a partially fragmented side elevation of the crown pad; and

FIG. 3 is a top plan view of the crown pad.

Referring now to FIG. l of the drawings, safety helmet generallycomprises an outer shell 12, an inner shell 14 spaced from the outershell, and a relatively thick resilient liner 16 substantially fillingthe space between the inner and outer shells.

The inner and outer shells are formed of semi-flexible, relativelystiff, material which will flex or bend only under considerable pressureand which will return to its initial shape on release of that pressure.Such a material may he acrylonitrile butadiene styrene (commonly knownas ABS), which is a thermal-forming plastic sheet approximately .05 to.06 inch in thickness.

The intermediate resilient liner 16 is preferably formed of a foamedplastic material, such as foamed polystyrene. Such a material ischaracterized by being resilient and compressible under pressure whilehaving a relatively slow recovery rate in returning to its originalshape upon release of pressure. The lower peripheral edges of the innerand outer shells are covered by an edge bead 1S.

Within the helmet is positioned a cradle comprising a front head band2f) and a rear head band 22, each part being secured to inner shell 14by means of padded rivets 24. The head band components are secured toeach other by means of snap fasteners 26, which may pass through any oneof a plurality of holes 28 in the rear head band so as to adjust thehead band circumference to various sizes.

A chin strap (not illustrated) may be provided to insure that the helmetwill not be forced off the head of the wearer under impact.

Crown pad 30, as illustrated most clearly in FIGS. 2 and 3, comprises aresilient shock absorbing filler 32 which is encased between top cover34 and bottom cover 36. The ller 32 is preferably fabricated of urethanefoam, but can alternatively be made from foamed vinyl or other foamedplastic or the like. Both top and bottom covers 34 and 36, respectively,may be vinyl sheets heat sealed together at their periphery in the lformof simulated stitches 38. Covers 34 and 36 are non-porous, and

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the heat sealed seam between them prevents the passage of airtherebetween.

A pair of holes is provided near the center of top cover 34. These holesloosely receive a loop 42 (see FIG. l) which also passes through a pairof holes 44 in the inner shell, so that crown pad 30 is suspended fromthe inner shell by loop 42 which may be `formed of a suitable cordmaterial.

The upper face of the pad 3Q is normally spaced slightly from innershell so that air can enter the pad through holes 49. When the helmet isplaced on the head of a wearer, the pad is displaced upwardly by contactwith the head, thus reducing or eliminating this space. The weight ofthe helmet yon the head of the wearer and the tension in the chin straptend to expel some of the air within the pad through holes 40. Theexpulsion of some of the air facilitates the conformance of the crownpad to the head during normal wear. However, under sudden heavy impactto the helmet, the pad is jammed against the inner shell with sufficientforce to seal holes 40 against the under surface of inner shell 14, thustrapping the air remaining within the pad. At that moment the pad actsas a pneumatic cushion, absorbing applied loads resiliently.

Thus, the novel crown pad of this invention combines the desiredfeatures of conformability to heads of different shapes whilefunctioning as a pneumatic shock absorber under impact.

This invention may be further developed within the scope of thefollowing claims. Accordingly, the above specification is to beinterpreted as illustrative of only a single embodiment of thisinvention, rather than in a strictly limited sense.

I now claim:

1. In a safety helmet comprising a generally domeshaped shock resistingand shock absorbing shell, the improvement which comprises:

a resilient crown pad of suf`n`cient thickness to provide cushioningbetween the head of the wearer and the inner surface of the helmetshell;

means suspending said pad from the apex of the shell interior;

an envelope encasing said resilient pad, said envelope being non-porousexcept for a small orifice in the top central portion thereof, saidorifice being normally free from contact with the interior surface ofthe shell, thereby to allow free air flow to and from the interior ofsaid pad, said orifice upon sudden downward impact to the helmet beingclosed by face to face contact between the top of said envelope and theinterior surface of the shell, thereby to prevent the escape of air fromsaid pad.

2. A construction as defined in claim 1 wherein said suspension meanscomprises a liexible member anchored to the helmet shell and passingthrough said orifice and anchored within said crown pad.

References Cited UNITED STATES PATENTS 1,539,558 5/1925 Goldsmith 2 32,455,797 12/ 1948 Myers et al 2 6 3,292,180 12/1966 Marietta 2 33,111,674 ll/l963 Marietta 2 3 3,241,154 3/1966 Aileo 2 3 JORDANFRANKLIN, Primary Examiner.

J. R. BOLER, Assistant Examiner.

1. IN A SAFETY HELMET COMPRISING A GENERALLY DOMESHAPED SHOCK RESISTINGA SHOCK ABSORBING SHELL, THE IMPROVEMENT WHICH COMPRISES: A RESILIENTCROWN PAD OF SUFFICIENT THICKNESS TO PROVIDE CUSHIONING BETWEEN THE HEADOF THE WEARER AND THE INNER SURFACE OF THE HELMET SHELL; MEANSSUSPENDING SAID PAD FROM THE APEX OF THE SHELL INTERIOR; AN ENVELOPEENCASING SAID RESILIENT PAD, SAID ENVELOPE BEING NON-POROUS EXCEPT FOR ASMALL ORIFICE IN THE TOP CENTRAL PORTION THEREOF, SAID ORIFICE BEINGNORMALLY FREE FROM CONTACT WITH THE INTERIOR SURFACE OF THE SHELL,THEREBY TO ALLOW FREE FLOW TO AND FROM THE INTERIOR OF SAID PAD, SAIDORIFICE UPON SUDDEN DOWNWARD IMPACT TO THE HELMET BEING CLOSED BY FACETO FACE CONTACT BETWEEN THE TOP OF SAID ENVELOPE AND THE INTERIORSURFACE OF THE SHELL, THEREBY TO PREVENT THE ESCAPE OF AIR FROM SAIDPAD.